Added postgresql.

Added user and database creation to bootstrap.sh. Checks if user and database already exists.
Resolves #5 
Right, Sql doesn't allow database creation in a multi-line block (like an if block). That's why it's by itself.
http://stackoverflow.com/questions/18389124/simulate-create-database-if-not-exists-for-postgresql/18389184#18389184
This will cause an error message from psql, but it won't stop the build or rollback.